The present invention relates to interactive programmable interfaces for liquid crystal display (LCD) keyswitches and in particular to an on-line interactive programmable interface between a high speed data port of a computer and LCD keyswitch devices. The invention also relates to input/output devices having relegendable LCD keyswitches for use as stand-alone devices having an on-board microprocessor and for use in conjunction with a computer.
International Patent Publication No. WO 85/01596 discloses tactile function keys comprising relegendable keyswitches to provide a set of self-identifying function keys which can interface with any computer or dumb terminal. It was contemplated in this publication that each of the function keys should be independently programmable. However, the emphasis was placed throughout the publication on providing a keyset and at least one data set corresponding to the keys in the keyset. To alter the data displayed on the relegendable keyswitches, the data set is strobed to the keys in the keyset. Particular data for a display is stored in a corresponding memory location so that when a refresh or strobe signal is received the data from each memory location applicable to a keyset is transferred to the keyswitch displays.
WO 85/01596 also discloses relegendable keyswitches formed into a peripheral keypad which is interfaced to a computer using an interface circuit which functions as described above. A modified keyboard having a strip of relegendable keyswitches is also disclosed. Data set transfer is conducted via the standard keyboard interface.
Similarly, EP-A-0 226 392 relates to a display key comprising a relegendable keyswitch and a keyboard formed of such keyswitches. Display commands indicative of information to be displayed on the displays of the keys are assigned to memory locations which are accessed sequentially to transfer the display commands (data) to the key displays. Again, the emphasis in this publication is placed on an entire keyset being changed, for example, from upper case letters to lower case letters by the operation of the "shift" key or from a conventional QWERTY keyboard layout to some other array or language alphabet. The entire keyboard of a typewriter could be shifted from Roman to Greek to Japanese characters or to any other character set by an appropriate instruction. A further example includes an application program that is menu driven which is arranged to display the possible menu selections on the keys themselves. Thus, at different times a key can be used to cause the key displays to change. In each case, an entire new keyset is downloaded from memory to the displays.
EP-A-0 221 698 also discloses a display key comprising a relegendable keyswitch. The displays are LCDs (liquid crystal displays) made up of a matrix of sixteen rows and twenty four columns. Each dot or pixel in the matrix is assigned a location in the memory associated with the display driver circuitry of each key. In all embodiments described in this publication the "refreshing" and resetting of the displays is performed collectively, for example, the reset code for all displays is performed through a dedicated conductor common to all the display drivers.
As demonstrated in the aforementioned publications, it was believed that data sets should be altered in their entirety rather than individual keyswitch display data locations being addressed and altered. Discrete data cannot be transferred using the interface architecture disclosed in these publications.
Data input devices and more particularly point-of-sale devices are discussed in US-A-5,233,167. The publication discloses a point-of-sale device for use in a retail goods or services facility and is configured as a multi-function terminal having a built-in microprocessor. A keyboard for data entry is arranged in key blocks relating to particular attributes of the goods or services. The keyboard can be programmed for different attributes for different key block designations. A particular designation can be changed visually by substituting a replaceable overlay on the keyboard. To alter the designations of the key blocks, a host computer must reinterpret the code generated when a key is pressed. Once any designation has been changed the appropriate overlay must be sought and placed on the keyboard. This arrangement is suitable only in limited applications, for example, a shop dealing in a very limited range of goods or providing a service of limited scope. No interactivity between the controlling processor (a host computer) and the keyboard designations is illustrated.
IBM Technical Disclosure Bulletin, Vol. 29, No. 8, January 1987, New York, U.S., page 3636 discloses a mouse button layout employing full function keys.
IBM Technical Disclosure Bulletin, Vol. 26, No. 9, February 1984, New York, U.S., pages 4582-4583 discloses a keyboard with optically changeable key symbols.
The present invention discloses interfacing means developed to provide an on-line, interactive and real-time interface using the standard parallel port of a personal computer (PC) as the connection port to LCD devices comprising keyswitches grouped to form a keyboard or keypad. The keyboard or keypad can be formed by using LCD keyswitches only or a combination of LCD keyswitches and traditional keyswitches. The keyboard or keypad can be configured either as an integral part of a machine or as an attachable unit in either a fixed or mobile application. Further disclosed are data input/output devices operational remotely of a computer, having an on-board microprocessor in communication with the keyswitches via the interfacing means of the invention. The invention relates to the interfacing means which include hardware circuitry designs, firmware and software either as individual components or as a combination. The LCD keyswitches are programmable at picture element (pixel) level which allows data to be displayed either alpha-numerically, in graphic form or as static or moving pictograms. The keyswitches allow a range of backlit hues to be programmed. The LCD keyswitches exist in the prior art as exemplified by GB-A-2 150 722 (Muller) or EP-A-0 232 137 (Dowty Electronic Components Limited) and are not the subject of this invention.
This invention specifically covers the interfacing between computers and LCD keyswitches of the prior art which allows applications programs running on a computer such as a PC to communicate in an immediate, on-line and interactive way with a matrix of keyswitches to display alpha-numeric, graphic or pictogram information with or without backlit colour. The invention also covers devices using such an interface and remote devices capable of running programs from memory and adaptable for connection to a computer.
It is thus an object of the present invention to provide an improved programmable interface circuit for relegendable LCD keyswitches and to provide data input and point-of-sale devices exhibiting high-speed, on-line interactivity between the LCD keyswitches and a controlling processor.
According, the present invention provides an interface circuit for interfacing a matrix of relegendable liquid crystal display (LCD) keyswitches to a controlling processor, the circuit comprising:
means for addressing each LCD keyswitch; PA1 means for transferring display data to each LCD keyswitch; and PA1 means for reading data from each LCD keyswitch PA1 for transferring data representative of a desired function of a keyswitch from the controlling processor to the interface circuit for display on the LCD keyswitch so that, when that keyswitch is activated, the keyswitch is read by the circuit which allows the controlling processor to execute the indicated function represented on the display of the LCD keyswitch, PA1 characterised in that each LCD keyswitch is individually addressable and separately relegendable so that high speed, on-line interaction between each LCD keyswitch and the controlling processor is facilitated for substantially immediate relegending or refreshing of the display on each LCD keyswitch. PA1 means for establishing the current function of each keyswitch within a matrix; PA1 means for transmitting data to the relegendable LCD to display an alpha-numerical, graphical or pictogram image representative of the current or desired keyswitch function; and PA1 means for providing a signal to the controlling processor to enact the function represented on the LCD keyswitch when the keyswitch is activated. PA1 means for displaying on each LCD keyswitch an image representative of the data to be introduced or command to be executed; PA1 means for selecting or enabling each keyswitch; PA1 means for reading or sensing when each keyswitch is activated; PA1 means for transmitting the data or command to the controlling processor; and PA1 means for individually and separately altering the representative image on the display and the data to be introduced or command to be executed by a LCD keyswitch when the keyswitch is activated.
The circuit further comprises:
The circuit further comprises:
Advantageously, at least one LCD keyswitch within the matrix is assigned a macro comprising a plurality of functions executable by a single keystroke of the keyswitch.
The interface circuit may also include memory circuits for holding default instructions or initialisation commands and start-up data and for storing program instructions and/or data representative of the images for display on each LCD keyswitch.
Advantageously, Read Only Memory (ROM) is provided on the circuit to hold default instructions or initialisation commands for the LCD keyswitches and in which Random Access Memory (RAM) is provided on the circuit for storing data representative of the images used for a particular application or program operating on the controlling processor.
In a preferred arrangement, the RAM is preloaded with application or program instructions so that a central processor unit (CPU) in the interface circuit is independent of the controlling processor.
The controlling processor may comprise a computer in communication with the interface circuit via the parallel port of the computer.
Optionally, the controlling processor comprises an on-board microprocessor in direct communication with an interface circuit CPU.
The present invention further provides a data input device comprising a matrix of relegendable LCD keyswitches and an interface circuit for interfacing the device with a controlling processor, the keyswitches comprising LCDs for displaying an image representative of the keyswitch function characterised in that each keyswitch in the matrix is individually addressable and separately relegendable so that high speed, on-line interaction between each LCD keyswitch and the controlling processor is facilitated for substantially immediately relegending or refreshing of the display on the LCD keyswitch.
The interface circuit of the data input device includes a driver circuit having memory circuits to store data representative of the image displayed and includes a refresh function to retain the image on the display until a reset signal or new data is received.
The invention further provides a data input device comprising an interface circuit and a matrix of LCD keyswitches, each keyswitch being assigned a specific function changeable on operation of any one keyswitch. This arrangement is adaptable for use with a menu driven program running on the controlling processor or computer, each component of the menu being represented on the LCD keyswitches. Thus, when one keyswitch is pressed one or more of the other keyswitch images will change to represent the new menu.
The data input device may comprise either a keyboard, a keypad or a keystrip.
Preferably, the data input device includes a pointer device.
The data input device is adaptable for logging data received remotely wherein the data to be logged is displayed on the LCD keyswitch and said data is entered to memory by activating said keyswitch to confirm data entry.
The data input device interacts with software running on the controlling processor so that imbedded instructions or functions within the software are represented by images on the LCD keyswitches and are implemented by activating said keyswitches.
Advantageously, visual cues normally displayed on a computer visual display unit (VDU) are displayed or symbolically represented on the LCD keyswitches.
The data input device incorporates a user help system in which commands or instruction cues are displayed or symbolically represented on the LCD keyswitches. Preferably, the cues are concurrently displayed on the VDU.
The data input device may be used in conjunction with a computer running a graphical user interface (GUI) environment in which option button icons are displayed on the LCD keyswitches.
The present invention yet further provides a point-of-sale device comprising a matrix of relegendable LCD keyswitches and an interface circuit for interfacing the device with a controlling processor wherein point-of-sale data is selectively representable on each LCD keyswitch such that when a keyswitch is activated the data represented thereon is entered as part of a transaction, each LCD keyswitch being individually addressable and separately relegendable so that high speed, on-line interaction between each LCD keyswitch and the controlling processor is facilitated for substantially immediate relegending or refreshing of the display of the LCD keyswitch.
Advantageously, the data presented on the LCD keyswitches is representative of a point-of-sale function. Optionally, the data presented on the LCD keyswitch is representative of a parameter relating to a sale item in a transaction.
The point-of-sale device may include a card reader and a card reader interface in communication with the interface circuit wherein data read from a card is used in the transaction. The data read from a card may be displayed on a screen so that security details may be checked or compared.
Advantageously, the point-of-sale device has at least two input/output (I/O) ports, the first port comprising a communication link between the point-of-sale device and a computer and the second port comprising a communication link to a peripheral device in which the communication link comprises a network such as a local area network (LAN).
The peripheral device may be a modem, a cash drawer driver, a printer, a computer or a second point-of-sale device.
The second and subsequent I/O ports are provided with Universal Asynchronous Receiver/Transmitter (UART) circuits for data transfer.
The present invention provides a point-of-sale device having a housing to facilitate the interchangeability of matrices of relegendable LCD keyswitches or standard switches, LCD screens, printing devices, magnetic strip card readers and I/O port driver circuits.
The present invention further provides a housing suitable for the construction of a point-of-sale device, the housing comprising an upper plate and a lower plate, the upper plate having a first aperture for receiving a card swipe guide and a second aperture for receiving a one or more LCD keyswitch (matrix) modules forming the functional part of the device and the lower plate having means for receiving circuit boards and receivers for holding the upper plate in snap engagement.
The housing includes apertures for I/O ports of which a primary port facilitates the connection of the device to a computer and the secondary and subsequent ports facilitates the connection of UART or driver circuits to peripheral devices.
The major breakthrough addressed by this invention is the real-time, interactive and on-line facilities provided. The invention may include the use of a terminate and stay resident (TSR) program, a driver circuit or a composite of both program and driver circuit, which is/are optionally installed in the PC to provide an interface between the application program developer or user and the hardware and firmware of the keyboard/keypad.
This software program (TSR or driver or a composite of both) allows the application developer or user access the keyboard/keypad or to an individual key by using simple function calls. The program must co-exist with other program drivers, and must not interfere with program chains, interrupt handlers, other TSRs, other applications, memory management, task switches etc. The program instructions remove the complexities and dangers of peripheral interfacing from the application program developer or user. The interface circuit provides a secure communication to and from the keyboard/keypad. The connection between the parallel port and the interface circuit of the keyboard/keypad is through a standard 25-way cable.
The interface circuit hardware and firmware and the keyboard/keypad circuit coupled with the interface software program running on the computer allows data be communicated in a fast, efficient and interactive way with address/data signal integrity.
Detailed schematic drawings of working embodiments of the interface circuit are discussed hereinafter and illustrate the interaction of LCD keyswitch and traditional keyswitch matrices in combination. Also discussed are devices having an interface circuit for use in data input or input/output. Further arrangements include those in which the interface circuit comprises a standard magnetic strip card reader where the interface circuit is used as a point-of-sale device, for example. The keyboard/keypad layout presented is for example only and limitations to the combination of keys is only a factor of the printed circuit board (PCB) layout. The interface circuit is adaptable to interface any number of keyswitches either as LCD keyswitches only or in combination with standard tactile keyswitches, for tactile keyswitches only, touch sensitive keyswitches or with membrane touch keyswitches, i.e. with any keyswitch which has an electrical output.
The keyswitch depress and release signals are communicated to the PC through the parallel port connector block in the interface circuit. A major advantage disclosed is that the keystroke information signals can be packed into the PC's existing keyboard buffer as if the data had come from a standard QWERTY keyboard. This facility allows the device comprising the LCD keyswitches to act as if it was a QWERTY keyboard. The keyswitch data is also available to the application program by simple function calls. This interface design allows the identification of "stuck keys" so that the keyboard continues to operate its normal functions whilst handling a problem key device.
The present invention which combines hardware, firmware and software facilitates a multi-tasking environment and provides data buffering for efficient performance. The software and/or firmware program (TSR, driver or composite or both) for controlling the LCD images schedules all outgoing events for a "safe" time and tries to respond "immediately" to any relevant incoming events. The program also facilitates a user or applications developer such that access to every feature available is allowed without reference to other features and is not related directly to how the interface circuit operates, other than to the relevant applications codes (e.g. error-handlers etc).
The interface circuits illustrated can be configured in a variety of ways using different components. The fundamental techniques facilitate control of the signal, data, address and ancillary lines combined with the programming of the central processor unit (CPU).
The interactive, on-line and real-time communication facility now available between the keyswitches and the PC provides an easy to use interface.
Each key on the keyboard/keypad is in fact an individual screen with or without backlit hues which can display alpha-numeric text, graphic or pictogram images.
The present invention may also be utilised to avoid complex keystroke combinations to execute simple instructions. A computer input device incorporating the present invention is therefore easier to operate and capable of immediate use as a practical business or operational tool without new users feeling intimidated into the necessity of having to gain a detailed knowledge of how a PC works. The combination of devices and techniques described herein and LCD keyswitches either on their own or in combination with traditional keyswitches will allow interactive, real-time on-line assistance to the user, to easily exercise choice from complex options with a simple keystroke.
The interface circuits outlined can be easily adapted using similar circuitry, firmware and software to provide interfaces to work stations, other programmable devices and equipment or be adapted for use as a stand-alone unit for connection to any high speed port or data bus of a computer.
The invention will hereinafter be more particularly described with reference to the accompanying drawings which show schematically, by way of example only, three embodiments of circuit used to provide an interface according to the invention. The drawings also illustrate various embodiment of apparatus incorporating the interface circuit of the present invention in various use application.